a. Field of the Invention
The invention relates to a light source module.
b. Description of the Related Art
FIG. 1 shows a cross-section diagram illustrating a conventional light source module 100. Referring to FIG. 1, a light source module 100 includes a casing 102 and a light bar 104. At least one LED 106 is provided on a surface of the light bar 104. The light bar 104 is disposed in the casing 102 in a direction substantially parallel to a light incident surface 110a of a light guide plate 110. A light beam emitted by the LED 106 is reflected by side reflective layers 108 and then enters a front section of the light guide plate 110. Referring to the light paths shown in FIG. 2, since the light bar 104 is substantially parallel to the light incident surface 110a, yellowish white light Iy is incident on the light guide plate 110 at an angle α of about 35 to 80 degrees. Under the circumstance, the number of times the yellowish white light Iy is reflected within a specified distance is larger then the number of times the bluish white light Ib is reflected. In other words, the yellowish white light Iy is reflected to a great extent in the front section of the light guide plate 110 to result in a yellowish front section of the light guide plate 110 and thus decrease the overall color uniformity.
Further, as shown in FIG. 3, Taiwan patent publication no. 200834178 discloses an edge-lighting backlight module 200 having a reflective sheet 204. The reflective sheet 204 holds an LED 202 and slants inside a casing 206, so the reflective sheet 204 makes an angle γ to a light incident surface 208a of a light guide plate 208 so as to increase the amount of emitting light of the LED 202 received by the light guide plate 208. However, the manner that the reflective sheet 204 is disposed on a slant may improve the light utilization efficiency but fails to increase the overall color uniformity.